There were a couple of significant acquisitions in the mobile advertising space towards the end of last week. Mobile ad network AdMob announced that it has entered into a definitive agreement to acquire the assets of AdWhirl, which provides a mobile advertising mediation solution. Commenting on the acquisition, AdMob CEO Omar Hamoui said that by offering this first ever open source ad mediation solution, its goal was to provide a much needed open, unbiased and transparent tool for mobile publishers who would like to build financially rewarding businesses that are fuelled by advertising.

AdMob says it will expand on AdWhirls mediation product to create enhanced developer tools that will be offered as an open source mobile ad mediation solution. This, it says, will provide a transparent and unbiased solution for developers to allocate their inventory among multiple mobile ad networks and maximise the fill rates and revenue potential of their applications.

AdMob says it expects to make these offerings available in the coming weeks. In the interim, publishers will be able to continue utilising AdWhirls tools just as they have done previously.

AdMob was not the only company on the acquitision trail. Also last week, the Orange France Telecom Group bought 100% of Unanimis, which describes itself as the UKs largest exclusive digital advertising network. Through the combination of Unanimiss ad network and Oranges mobile and web assets, advertisers, buyers and media agencies will be able to reach over 71.5% of the UKs online population and over 66% of the online population across UK, France, Spain and Poland.

Unanimis has exclusive online advertising relationships with brands such as the AA, Ticketmaster, ASOS, Gumtree and Shopping.com. The company will continue to operate under its brand name and will become part of the Orange Group Advertising Network, which offers advertisers and publishers an opportunity to reach new audiences by leveraging Oranges multi-screen assets across the PC, mobile and TV platforms.

“As 2008 marked the revolution in the mobile Internet space, so 2009 will see the major advances in digital and mobile advertising,” says Orange UK Chief Development Officer, Gerry McQuade. “The Orange mobile portal, Orange World, and our fixed portal, attract over 12 million monthly users, and with the advances in handset technology, coupled with new prices plans, this is set to rise even further. More companies are increasingly turning to the mobile Internet to enhance the way they advertise. A key part of our strategy at Orange UK is to grow and evolve our business in order to offer advertisers richer opportunities to engage with people. Combining the marketing opportunities offered through our mobile and web portal with the impressive inventory and sales expertise of Unanimis will give us huge strength, and allow us to help advertisers reach audiences in new and exciting ways.”